The present application discloses a transfer auger that screens/scalps foreign material out of granular fertilizer as it transfers from the storage bin to the seeding/fertilizing equipment subsequently used to apply the fertilizer in the field. This is a problem that “EVERY” farmer in the world encounters.
Granular fertilizer has been known to contain contaminants in the form of hardened clumps of fertilizer, stones, wood, bucket elevator bolts and other objects that don't belong in the desired fertilizer product to be applied to agricultural fields. If these contaminants enter the seeding equipment they can cause plugging, metering roller damage and misapplication of products, and can result in the cost of large repair bills and/or potential revenue loss.
To Applicant's knowledge, there is no other device in the market that is designed to screen fertilizer as it leaves a storage bin.
A previously marketed solution is a hydraulic unit called the Lump Buster, by Rainy Day Fabricating Inc., which installs on the end of an auger to “grind” the fertilizer as it passes through, but such a solution does not address the issue of the removal of other contaminants that may be present in the fertilizer, and may also create fertilizer dust, which can attract moisture and cause additional problems.
U.S. Pat. No. 4,095,705 proposes use of a combined auger and screening apparatus for loading of prilled fertilizer into an aircraft for aerial application of fertilizer to the field. An inlet hopper features a screen recessed into the open top end of the hopper and is supported on a wheeled frame shared by an auger conveyor that slopes upwardly from the underside of the hopper to an outlet end of the auger housing. A belt-driven system is operable to drive the auger shaft via an input pulley of the auger than carries an eccentric mass so as to cause a vibrational effect on the hopper to prevent bridging and tunneling of material therein.
Other devices for screening granular fertilizer are disclosed in U.S. Pat. Nos. 3,532,276 and 3,610,414, but these are not intended for use in transferring fertilizer from a storage bin to application equipment in a farm setting, and accordingly lack portability and an inclined conveyor operable to elevate material from the bottom outlet of a hopper bin into an air seeder or drill.
U.S. Pat. No. 3,411,757 discloses a loader for precision mixing of cement and features an auger whose inlet hopper features an input screen for filtering out of larger particles to prevent entry thereof to the auger inlet, but no vibrational mechanism is included to achieve optimum filtering through this screen.
Other known auger designs with built-in screening means include grain-screening augers, such as those disclosed in U.S. Pat. Nos. 2,706,046 and 4,684,458, but such designs employ screens that are incorporated into the auger tube, and accordingly only filter out unwanted material after it has already entered the auger tube. Stand alone grain cleaners are also known, but are not suitable for use in screening of granular fertilizer.
Applicant has developed a unique apparatus that combines screening and conveying functionality into a single unit in a manner not seen nor suggested by the prior art, and that may be used for the loading of granular fertilizer application equipment from a storage bin, or other similar contexts that may also require combined screening and conveyance functionality.